EL-Edfawy Y. M., S. Mohamed and E.M. Aly( 2021). Effect of k-sources in combination with gibberellic acid on maize production under water stress in sandy soilMenoufia J. Soil Sci., Vol. 6 February (2021): 1-17
Abstract: A field experiment was conducted along the two successive summer seasons of 2019 and 2020 under sandy soil conditions at Ismailia Agricultural Research Station. This study aim to evaluate the effect of K sources i.e. K-silicate and K- humate, combined with gibberellic acid application under different irrigation levels on yield characters and NPK uptake by maize plant (Zea maize L.). The experimental treatments were arranged in a split –split plot design as follows: (1) three irrigation levels were assigned as main plots i.e. 100% (I1) 80 %(I2) and 60 %(I3) of maize evapotranspiration (ETc), (2) three treatments of K-source as foliar application were arranged as sub plot i.e. 0, K-humate at rate of 4 g L-1 and K-silicate at rate of 150 mg L-1 Si (3) three application rates of gibberellic acid 0 (G0), 100 (G1) and 150 (G2) mg L-1were arranged as sub-sub plots. The obtained results indicated that the heist values of grain yield, straw yield and NPK- uptake by plant were recorded at treatment of I2*Khumate*GA1. Soil content of available N was significantly increased with the foliar spraying of the K-silicate, Khumate and the different levels of gibberellic acid, but not significantly affected by irrigation levels. Soil available P was not significantly affected by different treatments while, soil available K was significantly affected by irrigation level, K-silicate and Khumate but not significantly affected by the different levels of Gibberellic acid.
Keywords: (Maize; Irrigation level; K-humate; K-silicate; , Gibrillic acid)